The fire axe was used by Toni Cipriani in order to kill Giovanni Casa during the mission Dead Meat in Grand Theft Auto: Liberty City Stories. The axe is also a weapon of choice for the Diablos. The axe is an average weapon that deals the same amount of damage as the Baseball Bat and is one of the only few melee weapons the player cannot perform a swing hit whilst playing Grand Theft Auto: Vice City Stories.
Toni Cipriani with a fire axe in Grand Theft Auto: Liberty City Stories.
The Fire Axe was scheduled to be released in Grand Theft Auto V, although the weapon was cut before the game was released. An image of it can be found in the game files. It was most likely replaced by the Hatchet.